Field of Invention
[0001] This invention relates to a motion generator i.e. a form of robotic system. More
particularly, the invention relates to a motion generator having a moveable end effector,
for use, for example, in motion systems such as motion platforms, and to methods of
using motion generators and motion systems.
Background
[0002] Motion generators are used in a variety of applications, including motion simulation
(for example, flight simulators, driving simulators), robotics, 3D printing, vibration
and seismic simulation. An early type of motion generator is disclosed in
GB1160471. The most common type of motion generator currently used in motion simulation is
the Stewart platform (or "hexapod").
US2016/0140862 discloses such a hexapod. This is a type of parallel robot that has six actuators,
attached in pairs to three configurations on the baseplate of a platform and crossing
over to three mounting points on a top plate. Devices or payloads such as a human
user placed on the top plate, usually in some form of cockpit, driver area or model
vehicle, can be moved in the six degrees of freedom in which it is possible for a
freely-suspended body to move, i.e. the three linear movements x, y, z (lateral, longitudinal
and vertical), and the three rotations (pitch, roll and yaw). Alternatively, the payload
may also be a further motion generator which is said to be in series with the first.
[0003] A motion simulator is a mechanism that can create, for an occupant, the effects or
feelings of being in a moving vehicle and includes a motion system i.e. at least one
motion generator and an associated control system. Motion simulators are used, professionally,
for training drivers and pilots in the form of driving simulators and flight simulators
respectively. They also are used, industrially, in the creation, design, and testing
of the vehicles themselves.
[0004] Professional motion simulators used as driving and flying simulators typically synchronise
a visual display - provided for example by a projection system and associated screens
and audio signals with the movement of a carriage (or chassis) occupied by the driver
or pilot in order to provide a better sensation of the effect of moving. The advent
of virtual reality (VR) head-mounted displays (HMDs) makes the aspect of an immersive
simulation less costly with current motion systems and has the ability to deliver
virtual reality applications to leisure uses such as in passive amusement park or
arcade driving, riding-first-person, or flying rides and in active gaming, where one
or more players has some control over the driving, riding, flying or first-person
game experience.
[0005] The type of hexapods typically used in motion simulation for human participants typically
have a bandwidth of up to about 20Hz. This means that they can create oscillatory
movements and vibrations of a consistent amplitude, with a frequency of up to 20 times
per second, beyond which the amplitude of the movements reduces as the frequency increases.
This is sufficient for most car suspension movements, but it does not transmit the
frequency content associated with vibrations from the car engine, tyre vibrations,
road noise and the sharp-edged kerbs on race tracks. A low bandwidth also means the
signals are delayed, meaning the driver cannot respond as quickly.
[0006] Current motion generators, especially those intended for high-end use such as in
military and commercial flight instruction and training applications, are typically
very large, heavy, complex and expensive. Their complexity necessitates extensive
programming and maintenance, further extending the cost. An example of a motion generator
in a flight simulator is disclosed in
US2012/301853. Dedicated driving simulator motion systems have been developed by the likes of McLaren/MTS
Williams/ABD and Ansible, but these tend to be extremely mechanically complex, and
therefore expensive, featuring precision machined custom components and often expensive
linear motors. These dedicated driving simulator motion systems are more responsive
than hexapods when moving in some directions but are still limited in others. The
use of ballscrews in systems is disadvantageous in that whilst good at establishing
position they inhibit force transfer, and can only achieve a lower bandwidth, and
so result in a less natural experience for a human user.
[0007] EP1063064 discloses a six degree of freedom travelling system including a cage for a human
user(s). The cage's configuration is maintained by eight cables or wires. The system
requires a pair of overhead suspension cables and an overhead connection which is
disadvantageous in several respects. First, it requires an overhead attachment limiting
the location of the system. Second, the overhead suspension cables increase the overall
dimensions of the system and make it unsuitable when a compact installation is required.
[0008] US2012/0080578 discloses a six degrees of motion platform including a platform supported on a suspension
unit which is mounted on a base. The platform, which is particularly designed for
planning radiation treatment by simulating movement of a patient to be treated in
relation to a radiation therapy device, is moved on the suspension unit by six actuator-controlled
nonmagnetic/non-metallic strings.
[0009] WO2017/037458 discloses a limited movement cable/actuator-controlled motion platform system including
a carriage which is capable of movement in the horizontal plane only. The motion platform
system relies on a secondary ram-operated motion system for vertical movement. The
system is quite limited in its application.
[0010] US4666362 discloses a three to six degree of freedom cable/actuator-controlled motion generator
including a moving platform (end effector) supported on a base platform by an extensible
or telescoping central post. In this system the motors must be constantly energised
to keep the cables in tension and the end effector in position. This requires large
motors or a gearbox to generate the continuous torque, which limits the bandwidth
of the system.
[0011] US2017/0053548 discloses a motion generator including a cable/actuator-controlled platform which
is slidable on a large low friction fixed base and which allows for significant horizontal
movement of the platform. The cables and actuators are disposed around the periphery
of the large base, facilitating the significant horizontal movement of the platform.
A hexapod is in turn mounted on the platform and supports a model cockpit in order
to provide further movement. The system is not compact and requires control of both
the cable/actuator -controlled platform as well as of the hexapod.
[0012] GB2378687A discloses a motion generator having a platform mounted on motion units which move
on parallel rails driven by linear motors. The arrangement is somewhat complex, and
expensive to produce.
US2016/236100 discloses a six degree of freedom hexapod-based motion platform with a structure
which provides support to the platform to reduce the load on the actuators.
[0013] It is an object of the present invention to provide a system which may be capable
of motion in the six degrees of freedom, which may be haptic and may be capable of
human input but which, compared to existing systems, may be mechanically simpler,
may be cheaper to build, which may have high backdrivability, which may be controlled
at higher frequencies than anything in a comparable price bracket and/or which may
be manufactured to accompany a virtual reality headset.
Summary of the Invention
[0014] According to one aspect of the invention there is provided a motion generator having
a moveable end effector, which may, for example be, a platform, vehicle chassis or
replica thereof and may or may not support a user, the motion generator comprising:
an end effector, a stationary support, a first set of elastic elements interconnecting
the end effector and the stationary support; a set of tensile members; in which the
end effector is supported within the stationary support by the elastic elements; and
a set of actuators in which the motion generator further comprises at least six rockers
each rocker being pivotally mounted at one end thereof on the stationary support,
and each rocker having an other end; the set of tensile members comprising: at least
six elongate tensile members, each elongate tensile member having one end connected
to the other end of a rocker and the other end connected to one of a second set of
elastic elements which are fixed to a frame and/or a base; a set of connecting elements
connecting the other end of each rocker to the end effector, and in which each one
of the set of tensile members is independently adjustably tensioned by an associated
actuator to move the other end of the rocker,
which rocker movement causes movement of a connected connecting element leading to
movement of the end effector.
[0015] Typically, the motion generator of the invention is arranged on a surface whereby
the end effector is moved in relation to the surface. The surface may be for example
a floor in a building where the motion generator is located
[0016] The motion generator of the invention may be used in a variety of applications, including
motion simulation (for example, flight simulators, driving simulators), robotics,
3D printing, vibration and seismic simulation.
[0017] A motion generator in accordance with the invention can be constructed of relatively
light weight components. It may be stiff, and its motion is relatively frictionless
compared to Stewart platforms and so may be controlled to produce accelerations, motions,
forces or moments, of high frequencies, in six degrees of freedom up to and in excess
of 50 Hz and more advantageously 100 Hz. Such high frequency (or "bandwidth"), which
permits, for example, much more realistic simulation of vehicle behaviour in different
scenarios such as racetrack, emulating racetrack features such as sawtooth kerbs,
off-road and battlegrounds has not been possible with prior art 6 degrees of freedom
motion generators of similar or indeed much greater cost. The motion generator of
the invention may be backdrivable which is highly advantageous. Furthermore, the system
of the invention may be produced in a commercial format which is much more compact
compared to many prior art designs, and additionally, does not require overhead suspension
devices which limit installation options. Furthermore, a motion generator in accordance
with the invention may be readily installed in a typical building without onerous
structural building requirements, or the need for a special flat surface.
[0018] The actuators may comprise rotary electric motors. Other motors are contemplated
including rotary and guided linear variants of electric, hydraulic and pneumatic motors.
[0019] The second set of elastic elements may be fixed to the stationary support.
[0020] The actuators may be mounted on the stationary support but could be mounted elsewhere.
[0021] The rockers may be arranged for movement in a plane parallel with the end effector
when in a neutral condition or configuration. The plane may be parallel with the surface.
[0022] At least one of the rockers may move in a horizontal plane. Preferably all of the
rockers may move in a horizontal plane.
[0023] The tensile members may include an actuator-engaging surface. For example, the actuator-engaging
surface may be provided by a toothed belt or chain acting on a sprocket, or by the
use of a high friction coating. Alternatively, the tensile member may wrap once or
more times around a drum to increase adhesion between the tensile member and actuator.
[0024] The actuators may be independently controlled to vary the position of the rockers
independently.
[0025] For example, the actuators may be controlled by programmable control means.
[0026] The connecting elements may be resilient members. For example, the connecting elements
may be wire rope; high modulus polyethylene (HMPE) rope; carbon fibre tethers; rigid
rods with joints, rod ends, flexible straps or flexures at each end; fabric straps;
Kevlar; PBO (or "Zylon"); or Dyneema.
[0027] In a preferred embodiment, the motion generator is backdrivable that is to say the
motion generator applies little resistance to external forces being applied to it
- for example when a user supported by the end effector moves their weight around
- then the forces applied by the user causes the actuator motors to rotate. By measuring
the movement of the motors in response to the user's movement, the user's position
and movements can be inferred. The outputs relating to the user's position and/or
movements can be used to inform for example a control system, a visual display system,
and/or audio system.
[0028] According to another aspect of the invention there is provided a motion system, the
motion system comprising a motion generator in accordance with the invention and a
control system. The control system may comprise the programmable control means mentioned
above. The control system may be integrated with or remote from the motion generator.
[0029] According to another aspect of the invention there is provided a vehicle or driving
simulator including a motion generator or motion system according to the invention
and comprising at least one vehicle control means, such as a steering wheel, gear
change, or control pedal and an environment simulator such as means for projecting
a vehicle environment such as a racetrack, road, off-road scenario or battleground.
The environment simulator may include a virtual reality headset or projection system.
[0030] Motion generators and motion systems of the invention are useful in automotive and
automotive component testing and design. According to another aspect of the invention
there is provided method of vehicle or vehicle component design, the method comprising
the steps of first providing a motion generator according to the invention, or a motion
system according to the invention, or a vehicle simulator according to the invention,
then simulating a vehicle or component design feature or change and testing the effect
of that feature using the motion generator, motion system or vehicle simulator. The
output of the testing is test data.
[0031] According to another aspect of the invention there is provided game apparatus including
a motion generator or motion system according to the invention. The game apparatus
may be located within an amusement arcade for example, but equally may be for domestic
or commercial use. The game apparatus may include means for simulating an environment.
The means for simulating an environment may include display apparatus, virtual reality
apparatus, or projection apparatus.
[0032] According to another aspect of the invention there is provided a method of producing
a motion generator according to any one of claims 1 to 12, a motion system according
to claim 13, a game apparatus according to any one of claims 18 to 20, the method
comprising assembling a motion generator (10) having a moveable end effector, the
system comprising: an end effector (32), a stationary support (14), a first set of
elastic elements (60, 62, 64) interconnecting the end effector (32) and the stationary
support (14); a set of tensile members (92, 94, 96, 98, 100, and 102); in which the
end effector is supported within the stationary support by the elastic elements (60,
62, 64); and a set of actuators (80, 82, 84, 86, 88, 90); at least six rockers (36,
38, 40, 42, 44, 45) each rocker being pivotally mounted at one end thereof on the
stationary support, and each rocker having a free end; the set of tensile members
(92, 94, 96, 98, 100, 102) comprising: at least six elongate tensile members, each
elongate tensile member having one end connected to a rocker and the other end connected
to one of a second set of elastic elements (104, 106, 108, 110, 112, and 114) which
are fixed; a set of connecting elements (46, 48, 50, 52, 54, 55) connecting each rocker
to the end effector (32); and in which each one of the set of tensile members (92,
94, 96, 98, 100, 102) is independently adjustably tensioned by an associated actuator
(80, 82, 84,86,88,90) to move the free end of the rocker, which rocker movement causes
movement of a connected connecting element (46, 48, 50, 52, 54, 55) leading to movement
of the end effector (32). It will be appreciated that the method of production may
be simpler than with conventional motion generators.
Brief Description of the Drawings
[0033] Motion generators, motion systems, and driving simulators and their operation, uses
and production in accordance with the invention will now be described, by way of example
only, with reference to the accompanying drawings, Figures 1 to 10, in which:
Figure 1A is an elevation from one side of a motion generator in accordance with the
invention in a neutral configuration;
Figure 1B is an elevation from the front of the motion generator as shown in Figure
1A;
Figure 1C is a simplified plan view from below of the motion generator as shown in
Figure 1A;
Figure 1D is a perspective view of the motion generator as shown in Figure 1A from
above, front and one side;
Figure 2A is an elevation from one side of the motion generator of Figure 1 when in
a surge forward along the x-axis configuration;
Figure 2B is an elevation from the front of the motion generator as shown in Figure
2A;
Figure 2C is a simplified plan view from below of the motion generator as shown in
Fig 2A;
Figure 2D is a perspective view of the motion generator as shown in Fig 2A;
Figure 3A is an elevation from one side of the motion generator of Figure 1 when in
a sway laterally along the y-axis configuration;
Figure 3B is an elevation from the front of the motion generator as shown in Figure
2A;
Figure 3C is a simplified plan view from below of the motion generator as shown Figure
2A;
Figure 3D is a perspective view of the motion generator as shown in Figure 2A;
Figure 4A is an elevation from one side of the motion generator of Figure 1 when in
a heave vertically along the z-axis configuration;
Figure 4B is an elevation from the front of the motion generator as shown in Figure
4A;
Figure 4C is a simplified plan view from below of the motion generator as shown in
Figure 4A;
Figure 4D is a schematic perspective view of a motion generator as shown in Figure
4A;
Figure 5A is an elevation from one side of the motion generator of Figure 1 when in
a roll about the x-axis configuration;
Figure 5B is an elevation from the front of the motion generator as shown in Figure
5A;
Figure 5C is a simplified plan view from below of the motion generator as shown in
Figure 5A;
Figure 5D is a schematic perspective view of a motion generator as shown in Figure
5A;
Figure 6A is an elevation from one side of the motion generator of Figure 1 when in
a pitch about the y-axis configuration;
Figure 6B is an elevation from the front of the motion generator as shown in Figure
6A;
Figure 6C is a simplified plan view from below of the motion generator as shown in
Figure 6A;
Fig 6D is a schematic perspective view of a motion generator as shown in Figure 6A;
Figure 7A is an elevation from one side of the motion generator of Figure 7 when in
a yaw about the z-axis configuration;
Figure 7B is an elevation from the front of the motion generator as shown in Figure
7A;
Figure 7C is a simplified plan view from below of the motion generator as shown in
Figure 7A;
Figure 7D is a schematic perspective view of a motion generator as shown in Figure
7A;
Figure 8A is an elevation from one side of the motion generator of Figure 1 when in
a combined surge, sway and yaw configuration
Figure 8B is an elevation from the front of the motion generator as shown in Figure
8A;
Figure 8C is a simplified plan view from below of the motion generator as shown in
Figure 8A;
Fig 8D is a schematic perspective view of a motion generator as shown in Figure 8A;
Figure 9A is an elevation from one side of the motion generator of Figure 1 when in
a combined pitch and roll configuration;
Figure 9B is an elevation from the front of the motion generator as shown in Figure
9A;
Figure 9C is a simplified plan view from below of the motion generator as shown in
Figure 9A;
Fig 9D is a schematic perspective view of a motion generator as shown in Figure 9A;
and
Figure 10 is an elevation of a vehicle motion simulator incorporating a motion generator
of Figure 1 in use with a human user.
Description
A Motion Generator
[0034] A motion generator 10 in accordance with the invention is shown in Figures 1 to 9.
The motion generator 10 is mounted on a surface such as floor 12. The floor 12 may
be that of a test building in which the motion generator is located or may be an additional
floor unit which overlays another floor in use.
[0035] The motion generator 10 comprises a rigid frame 14, of tubular space-frame type construction
including lower elongate tubular elements 16, 18, 20, 22, 24, and 25, and longer tubular
elements 26, 28, and 30, which each have a lower horizontal portion co-planar with
tubular elements 16, 18, 20, 22, 24 and 25 to form the base of the frame 14 and which
each also have an upstanding portion 27, 29, and 31 respectively. Although tubular
components have been described, those components may be for example solid. The frame
14 may be made of materials such as steel, or other alloy, aluminium, aluminium alloy,
titanium or carbon fibre and in the form of separate components joined rigidly together
or could equally be moulded in one or more pieces. Suspended within the volume created
by the frame 14 is a platform (or end effector) 32 which is sufficient to carry a
significant load, for example a seat and a human user, or a vehicle chassis or monocoque.
The platform 32 has a triangular planform. Other planforms are anticipated for the
platform.
[0036] Six rockers 36, 38, 40, 42, 44, and 45 are pivotally mounted by one end thereof on
the ends of tubular elements 16, 18, 20, 22, 24, and 25 for movement in the horizontal
plane only. More rockers may be used. In other embodiments the rockers may move in
different planes according to the application and configuration. Whilst straight rockers
have been shown in this example other shapes are contemplated for the rockers including
L-shaped or V-shaped. Elongate struts 46, 48, 50, 52, 54, and 55 are in turn pivotally
mounted on the other ends of the rockers 36, 38, 40, 42, 44, and 45 respectively by
their lower ends. The opposing end of each strut 46, 48, 50, 52, 54, and 55 is pivotally
mounted to the corners of the triangular motion platform 32 in pairs 46, 45; 48, 50;
and 52, 54. The struts 46, 48, 50, 52, 54, and 55 could be replaced by tensile members
such as ropes, wire ropes or belts. One example of a suitable rope is M-Rig Max made
from Dyneema's DM20 by Marlow. A suitable wire rope is SS 1x7 / 1x19 Compacted made
by Certex. A suitable belt is Conti
® Synchrochain Carbon made by Continental.
[0037] As shown in Figure 1A, the platform 32 is supported by three elastic cords 60, 62
and 64 which are fixed at one end to the ends of upstanding portions 27, 29 and 31
of the frame 14, and fixed at the other end to rigid elongate members 70, 72 and 74
which are fixed to and depend from the base of the platform 30. An example of a suitable
elastic cord would be a Powerspring by Ibex Marina. Three or more elastic elements
in the first set of elastic elements are preferred. Too many elastic elements may
inhibit operation. Elastic cords 60, 62, 64 could be replaced by helically coiled
springs, or wire ropes connected to another elastic energy storage device such as
a torsion spring.
[0038] Six actuators, in the form of rotary electric motors, driving toothed capstans (one
suitable example of which would be an AKM2G Servo Motor by Kollmorgan with a synchronous
belt sprocket by Martin) 80 (referred to as "actuator 1" below), 82 ("actuator 2"),
84 ("actuator 3"), 86 ("actuator 4"), 88 ("actuator 5"), and 90 ("actuator 6") are
fixed to the base 12 or to the frame so that they are constrained from movement. The
actuators drive toothed belts 92, 94, 96, 98, 100, and 102 which connect at one end
thereof to the rockers and at the other end to the frame 14 or base 12 via a second
set of elastic elements in the form of elastic cords 104, 106, 108, 110, 112, and
114, which are anchored rigidly fixed to the frame 14 or base 12. Elastic cords 104,
106, 108, 110, 112, and 114 could be replaced by helically coiled springs, or wire
ropes connected to another elastic energy storage device such as a torsion spring
[0039] In use, each associated rocker, elastic cord, actuator and belt combination 36 104,
80, 92; 38, 106, 82, and 94; 40, 108, 84, 96; 42, 110, 86, 98; 44, 112, 88, 100; and
45, 114, 90, 102, (each combination being referred to in the description below by
the actuator number mentioned above) is controlled by computing means (not shown)
acting on the actuator to move the associated belt thus altering the state of the
connected rocker and elastic cord which affects the motion/position of the platform
32.
[0040] Some basic configurations of the motion generator will now be described with reference
to the further figures.
Neutral configuration
[0041] In the neutral configuration illustrated in Figure 1A-D, the motion platform 32 is
horizontal, suspended by the elastic cords 60, 62 and 64 with the rockers and elastic
cords in a neutral state.
Actuator number |
Rocker position relative to neutral state |
Actuator support spring length relative to neutral state |
1 |
Neutral |
Neutral |
2 |
Neutral |
Neutral |
3 |
Neutral |
Neutral |
4 |
Neutral |
Neutral |
5 |
Neutral |
Neutral |
6 |
Neutral |
Neutral |
Surge forward along the x-axis configuration
[0042] In the surge forward configuration shown in Figures 2A-D, the platform 32 is moved
forward by actuator-controlled movement of the rockers and connected elastic cords
into the states set out below.
Actuator number |
Rocker position relative to neutral state |
Actuator support spring length relative to neutral state |
1 |
Anticlockwise |
Extended |
2 |
Anticlockwise |
Contracted |
3 |
Anticlockwise |
Extended |
4 |
Clockwise |
Extended |
5 |
Clockwise |
Contracted |
6 |
Clockwise |
Extended |
Sway laterally along the y-axis configuration
[0043] In the sway sideways configuration shown in Figures 3A-D, which may simulate sideways
movement of a vehicle, the platform 32 is moved sideways by actuator-controlled movement
of the rockers and connected elastic cords into the states set out below.
Actuator number |
Rocker position relative to neutral state |
Actuator support spring length relative to neutral state |
1 |
Clockwise |
Contracted |
2 |
Anticlockwise |
Contracted |
3 |
Anticlockwise |
Extended |
4 |
Anticlockwise |
Contracted |
5 |
Anticlockwise |
Extended |
6 |
Clockwise |
Extended |
Heave vertically along the z axis configuration
[0044] In the heave upwards configuration shown in Figures 4A-D, the platform 32 is moved
upwardly by actuator-controlled movement of the rockers and connected elastic cords
into the states set out below .
Actuator number |
Rocker position relative to neutral state |
Actuator support spring length relative to neutral state |
1 |
Anticlockwise |
Extended |
2 |
Clockwise |
Extended |
3 |
Anticlockwise |
Extended |
4 |
Clockwise |
Extended |
5 |
Anticlockwise |
Extended |
6 |
Clockwise |
Extended |
Roll about the x-axis configuration
[0045] In the roll configuration shown in Figure 5A-D, the platform 32 rotates about its
longitudinal axis by actuator-controlled movement of the rockers and connected elastic
cords into the states set out below.
Actuator number |
Rocker position relative to neutral state |
Actuator support spring length relative to neutral state |
1 |
Unchanged |
Unchanged |
2 |
Clockwise |
Extended |
3 |
Anticlockwise |
Extended |
4 |
Anticlockwise |
Contracted |
5 |
Clockwise |
Contracted |
6 |
Unchanged |
Unchanged |
Pitch about the y axis configuration
[0046] In the pitch configuration shown in Figure 6A-D, the nose 33 of the platform 32,
is lowered by actuator-controlled movement of the rockers and connected elastic cords
into the states set out below
Actuator number |
Rocker position relative to neutral state |
Actuator support spring length relative to neutral state |
1 |
Clockwise |
Contracted |
2 |
Clockwise |
Extended |
3 |
Anticlockwise |
Extended |
4 |
Clockwise |
Extended |
5 |
Anticlockwise |
Extended |
6 |
Anticlockwise |
Contracted |
Yaw about the z-axis configuration
[0047] In the configuration shown in Figure 7A-D, the platform 32 rotates about a vertical
axis by actuator-controlled movement of the rockers and connected elastic cords into
the states set out below.
Actuator number |
Rocker position relative to neutral state |
Actuator support spring length relative to neutral state |
1 |
Clockwise |
Contracted |
2 |
Clockwise |
Extended |
3 |
Clockwise |
Contracted |
4 |
Clockwise |
Extended |
5 |
Clockwise |
Contracted |
6 |
Clockwise |
Extended |
[0048] In the above description, a number of configurations for the motion generator are
described. It will be appreciated that these two or more of these configurations can
be combined in many different ways to simulate different motion events.
Combined Surge, Sway and Yaw
[0049] In the configuration shown in Figure 8A-D, the motion generator is in a Combined
Surge, Sway and Yaw configuration.
Actuator number |
Rocker position relative to neutral state |
Actuator support spring length relative to neutral state |
1 |
Clockwise |
Contracted |
2 |
Clockwise |
Extended |
3 |
Clockwise |
Contracted |
4 |
Clockwise |
Extended |
5 |
Clockwise |
Contracted |
6 |
Clockwise |
Extended |
Combined Pitch and Roll
[0050] In the configuration shown in Figure 9, the motion generator is in a combined pitch
and roll. Configuration.
Actuator number |
Rocker position relative to neutral state |
Actuator support spring length relative to neutral state |
1 |
Clockwise |
Contracted |
2 |
Clockwise |
Extended |
3 |
Anticlockwise |
Extended |
4 |
Unchanged |
Unchanged |
5 |
Unchanged |
Unchanged |
6 |
Anticlockwise |
Contracted |
Test data
[0051] When a motion generator in accordance with the invention was tested it was found
to be capable of creating movements in all six degrees of freedom with a bandwidth
in excess of 50 Hz.
[0052] The motion generator can accelerate at more than 10m/s
2 in each translational direction and at more than 1000°/s
2 in each rotational direction. As the system is essentially a direct drive system,
lacking gearboxes or ballscrews it is capable of being backdriven.
[0053] Specific practical applications of the motion generator described above are now disclosed
below.
A vehicle simulator
[0054] A vehicle simulator 200 is shown in Fig 10. The vehicle simulator comprises a motion
generator 202 in which the platform (end effector) 204 supports a chassis replica
including a cockpit 206. Foot controls (not shown) and steering wheel 208 are mounted
within the cockpit 206. A user 112 sits in cockpit 206. A projection system including
screen 210 is provided which displays a driving environment simulation to a user.
In use, the user feels vibrations transmitted through the motion generator 202 to
the cockpit 206. A feature of the motion generator of the present invention is that
when the user moves in relation to the platform 204, for example lurching sideways
against a rolling movement of the platform, the motion generator is backdriven.
Vehicle design
[0055] In a method of designing a vehicle, using a motion generator in accordance with the
invention in a vehicle simulator as described above, a change in a vehicle parameter
may be simulated through operation of the motion generator in a particular manner
to reflect the change, and feedback from an experienced user in the simulator, and
measurements on the system are useful in determining whether the change results in
an improvement in vehicle performance in some aspect.
An arcade game apparatus
[0056] An arcade game apparatus, for example a racing car game apparatus, may have the same
main features as the vehicle simulator 200, but might, for example use a lower cost
virtual reality headset system to the projection system shown in Figure 10. Furthermore,
an arcade game operation of the motion generator in a particular manner to reflect
the change, and feedback from an experienced user in the simulator, and measurements
on the system are useful in determining whether the change results in an improvement
in vehicle performance in some aspect.
An arcade game apparatus
[0057] An arcade game apparatus, for example a racing car game apparatus, may have the same
main features as the vehicle simulator 200, but might, for example, use a lower cost
virtual reality headset system to the projection system shown in Figure 10. Furthermore,
an arcade game apparatus might include apparatus for coin, token, electronic payment
system or card-controlled operation.
[0058] A further application of the system could be as an arcade apparatus in which the
user's body movements are detected and acted upon by the system. For example, the
user may be standing on a board (e.g., surfboard or skateboard) which is fixed to
the table/end effector. By shifting their weight around and applying inertial forces
to the board, the user may shove or tilt the board in different directions. These
movements can be used as inputs to the simulation or game. The game may also still
generate movements and forces that push the board and the user in different directions.
[0059] This is possible due to the "backdrivability" of the system, meaning that its state
can easily be affected by movements or loads applied to the end effector. This is
possible due to the very low friction present in the actuators compared to a typical
hexapod system which might use a ballscrew actuator.
[0060] It will be appreciated that the arcade game apparatus could be adapted for domestic
use.
[0061] While a number of embodiments have been disclosed by way of example in this specification,
it should be understood that other variations are possible within the scope of the
present invention. For example, in certain applications, some or all of the rockers
may move in a non-horizontal plane. Such variations are not to be regarded as a departure
from the present disclosure, and all such modifications as would be obvious to one
skilled in the art are intended to be included within the scope of the following claims.
1. A motion generator (10) having a moveable end effector, the motion generator comprising:
an end effector (32), a stationary support (14), a first set of elastic elements (60,
62, 64) interconnecting the end effector (32) and the stationary support (14), and
a set of tensile members (92, 94, 96, 98, 100, and 102); in which the end effector
is supported within the stationary support by the elastic elements (60, 62, 64); and
a set of actuators (80, 82, 84, 86, 88, 90) characterised in that the motion generator further comprises at least six rockers (36, 38, 40, 42, 44,
45) each rocker being pivotally mounted at one end thereof on the stationary support,
and each rocker having an other end; the set of tensile members (92, 94, 96, 98, 100,
102) comprising: at least six elongate tensile members, each elongate tensile member
having one end connected to the other end of a rocker and the other end connected
to one of a second set of elastic elements (104, 106, 108, 110, 112, and 114) which
are fixed to a frame (14) and/or a base 12; a set of connecting elements (46, 48,
50, 52, 54, 55) connecting the other end of each rocker to the end effector (32);
and in which each one of the set of tensile members (92, 94, 96, 98, 100, 102) is
independently adjustably tensioned by an associated actuator (80, 82, 84, 86, 88,
90) to move the other end of the rocker, which rocker movement causes movement of
a connected connecting element (46, 48, 50, 52, 54, 55) leading to movement of the
end effector (32).
2. A motion generator according to claim 1 in which the actuators comprise rotary electric
motors.
3. A motion generator according to any preceding claim in which the second set of elastic
elements are fixed to the stationary support (14).
4. A motion generator according to any preceding claim in which the actuators (80, 82,
84, 86, 88, 90) are mounted on the stationary support.
5. A motion generator according to any preceding claim in which the rockers (36, 38,
40, 42, 44, 45) are arranged for movement in a plane parallel with the end effector
(32) when in a neutral condition or configuration.
6. A motion generator according to any one of claims 1 to 5 in which at least one of
the rockers (36, 38, 40, 42, 44, 45) moves in a horizontal plane.
7. A motion generator according to any preceding claim in which the tensile members include
an actuator-engaging surface, such as that provided by a toothed belt.
8. A motion generator according to any preceding claim in which the actuators are independently
controlled to vary the position of the rockers independently, optionally the actuators
are controlled by programmable computing means.
9. A motion generator according to any preceding claim in which the connecting elements
(46, 48, 50, 52, 54, 55) are resilient members.
10. A motion generator according to any preceding claim which is backdrivable.
11. A motion system comprising a motion generator according to any one of claims 1 to
10, and an associated control system.
12. A vehicle simulator (200) comprising a motion generator according to any one of claims
1 to 10 or a motion system according to claim 11, and at least one vehicle simulator
element, preferably the vehicle simulator element is selected from a cockpit (206),
driving cabin, foot control, steering wheel (208), or means for simulating an environment
(210).
13. A method of vehicle or vehicle component design, the method comprising the steps of
first providing a motion generator according to any one of claims 1 to 10, a motion
system according to claim 11, or a vehicle simulator (200) according to claim 12,
then simulating a vehicle or a vehicle component design feature or change and testing
the effect of that feature using the motion generator, the motion system or the vehicle
simulator.
14. Game apparatus for domestic or commercial use including a motion generator according
to any one of claims 1 to 10 or a motion system according to claim 11, and optionally
including means for simulating an environment (210) such as display apparatus, virtual
reality apparatus, or projection apparatus.
1. Bewegungsgenerator (10) mit einem beweglichen Endeffektor, der Bewegungsgenerator
umfassend:
einen Endeffektor (32), eine stationäre Stütze (14), einen ersten Satz elastischer
Elemente (60, 62, 64), die den Endeffektor (32) und die stationäre Stütze (14) miteinander
verbinden, und einen Satz von Zugelementen (92, 94, 96, 98, 100 und 102); wobei der
Endeffektor innerhalb der stationären Halterung durch die elastischen Elemente (60,
62, 64) gehalten wird;
und einem Satz von Aktuatoren (80, 82, 84, 86, 88, 90), dadurch gekennzeichnet, dass der Bewegungsgenerator ferner mindestens sechs Wippen (36, 38, 40, 42, 44, 45) umfasst,
wobei jede Wippe an einem seiner Enden schwenkbar an der stationären Stütze montiert
ist und jede Wippe ein anderes Ende aufweist;
der Satz von Zugelementen (92, 94, 96, 98, 100, 102) Folgendes umfasst: mindestens
sechs längliche Zugelemente, wobei ein Ende jedes länglichen Zugelements mit dem anderen
Ende einer Wippe und das andere Ende mit einem aus einem zweiten Satz von elastischen
Elementen (104, 106, 108, 110, 112 und 114) verbunden ist, die an einem Rahmen (14)
und/oder einer Basis 12 befestigt sind; einen Satz von Verbindungselementen (46, 48,
50, 52, 54, 55), die das andere Ende jeder Wippe mit dem Endeffektor (32) verbinden;
und bei dem jedes des Satzes von Zugelementen (92, 94, 96, 98, 100, 102) durch einen
zugehörigen Aktuator (80, 82, 84, 86, 88, 90) unabhängig einstellbar gespannt wird,
um das andere Ende der Wippe zu bewegen, wobei die Wippenbewegung eine Bewegung eines
verbundenen Verbindungselements (46, 48, 50, 52, 54, 55) bewirkt, die zu einer Bewegung
des Endeffektors (32) führt.
2. Bewegungsgenerator nach Anspruch 1, bei dem die Aktuatoren rotierende Elektromotoren
umfassen.
3. Bewegungsgenerator nach einem der vorstehenden Ansprüche, bei dem der zweite Satz
von elastischen Elementen an der stationären Stütze (14) befestigt ist.
4. Bewegungsgenerator nach einem der vorstehenden Ansprüche, bei dem die Aktuatoren (80,
82, 84, 86, 88, 90) an der stationären Stütze montiert sind.
5. Bewegungsgenerator nach einem der vorstehenden Ansprüche, bei dem die Wippen (36,
38, 40, 42, 44, 45) so angeordnet sind, dass sie sich in einer Ebene parallel zum
Endeffektor (32) bewegen, wenn sie sich in einem neutralen Zustand oder einer neutralen
Konfiguration befinden.
6. Bewegungsgenerator nach einem der Ansprüche 1 bis 5, bei dem sich mindestens eine
der Wippen (36, 38, 40, 42, 44, 45) in einer horizontalen Ebene bewegt.
7. Bewegungsgenerator nach einem der vorstehenden Ansprüche, bei dem die Zugelemente
eine Oberfläche einschließen, die mit dem Aktuator in Eingriff steht, wie sie beispielsweise
von einem Zahnriemen bereitgestellt wird.
8. Bewegungsgenerator nach einem der vorstehenden Ansprüche, bei dem die Aktuatoren unabhängig
voneinander gesteuert werden, um die Position der Wippen unabhängig voneinander zu
verändern, wobei die Aktuatoren optional durch programmierbare Rechenmittel gesteuert
werden.
9. Bewegungsgenerator nach einem der vorstehenden Ansprüche, bei dem die Verbindungselemente
(46, 48, 50, 52, 54, 55) federnde Elemente sind.
10. Bewegungsgenerator nach einem der vorstehenden Ansprüche, der rückwärtsfahrbar ist.
11. Bewegungssystem, umfassend einen Bewegungsgenerator nach einem der Ansprüche 1 bis
10 und ein zugehöriges Steuersystem.
12. Fahrzeugsimulator (200), umfassend einen Bewegungsgenerator nach einem der Ansprüche
1 bis 10 oder ein Bewegungssystem nach Anspruch 11 und mindestens ein Fahrzeugsimulatorelement,
wobei das Fahrzeugsimulatorelement vorzugsweise aus einem Cockpit (206), einer Fahrerkabine,
einer Fußsteuerung, einem Lenkrad (208) oder Mitteln zur Simulation einer Umgebung
(210) ausgewählt ist.
13. Verfahren zur Konstruktion eines Fahrzeugs oder einer Fahrzeugkomponente, wobei das
Verfahren die Schritte umfasst, zuerst einen Bewegungsgenerator nach einem der Ansprüche
1 bis 10, ein Bewegungssystem nach Anspruch 11 oder einen Fahrzeugsimulator (200)
nach Anspruch 12 bereitzustellen, dann ein Merkmal oder eine Änderung der Konstruktion
eines Fahrzeugs oder einer Fahrzeugkomponente zu simulieren und die Wirkung dieses
Merkmals unter Verwendung des Bewegungsgenerators, des Bewegungssystems oder des Fahrzeugsimulators
zu testen.
14. Spielgerät für den privaten oder kommerziellen Gebrauch, das einen Bewegungsgenerator
nach einem der Ansprüche 1 bis 10 oder ein Bewegungssystem nach Anspruch 11 einschließt
und optional Mittel zur Simulation einer Umgebung (210) wie Anzeigegeräte, Virtual-Reality-Geräte
oder Projektionsgeräte einschließt.
1. Générateur de mouvement (10) ayant un effecteur terminal mobile, le générateur de
mouvement comprenant : un effecteur terminal (32), un support fixe (14), un premier
ensemble d'éléments élastiques (60, 62, 64) interconnectant l'effecteur terminal (32)
et le support fixe (14), et un ensemble d'organes de traction (92, 94, 96, 98, 100,
et 102) ; dans lequel l'effecteur terminal est supporté à l'intérieur du support fixe
par les éléments élastiques (60, 62, 64) ; et un ensemble d'actionneurs (80, 82, 84,
86, 88, 90), caractérisé en ce que le générateur de mouvement comprend en outre au moins six basculeurs (36, 38, 40,
42, 44, 45) chaque basculeur étant monté pivotant à une extrémité de celui-ci sur
le support fixe, et chaque basculeur ayant une autre extrémité ;
l'ensemble d'organes de traction (92, 94, 96, 98, 100, 102) comprenant : au moins
six organes de traction allongés, chaque organe de traction allongé ayant une extrémité
connectée à l'autre extrémité d'un basculeur et l'autre extrémité connectée à un élément
d'un deuxième ensemble d'éléments élastiques (104, 106, 108, 110, 112, et 114) qui
sont fixés à un cadre (14) et/ou à une base (12) ; un ensemble d'éléments de connexion
(46, 48, 50, 52, 54, 55) connectant l'autre extrémité de chaque basculeur à l'effecteur
terminal (32) ; et dans lequel chaque organe de l'ensemble d'organes de traction (92,
94, 96, 98, 100, 102) est tendu de manière indépendante et réglable par un actionneur
associé (80, 82 84, 86, 88, 90) pour déplacer l'autre extrémité du basculeur, lequel
déplacement de basculeur provoquant un déplacement d'un élément de connexion (46,
48, 50, 52, 54, 55) connecté conduisant à un déplacement de l'effecteur terminal (32).
2. Générateur de mouvement selon la revendication 1, dans lequel les actionneurs comprennent
des moteurs électriques rotatifs.
3. Générateur de mouvement selon l'une quelconque des revendications précédentes, dans
lequel le deuxième ensemble d'éléments élastiques est fixé au support fixe (14).
4. Générateur de mouvement selon l'une quelconque des revendications précédentes, dans
lequel les actionneurs (80, 82, 84, 86, 88, 90) sont montés sur le support fixe.
5. Générateur de mouvement selon l'une quelconque des revendications précédentes, dans
lequel les basculeurs (36, 38, 40, 42, 44, 45) sont agencés pour se déplacer dans
un plan parallèle à l'effecteur terminal (32) lorsqu'ils sont dans un état ou une
configuration neutre.
6. Générateur de mouvement selon l'une quelconque des revendications 1 à 5, dans lequel
au moins un des basculeurs (36, 38, 40, 42, 44, 45) se déplace dans un plan horizontal.
7. Générateur de mouvement selon l'une quelconque des revendications précédentes dans
lequel les organes de traction comportent une surface de mise en prise d'actionneur,
telle que celle fournie par une courroie crantée.
8. Générateur de mouvement selon l'une quelconque des revendications précédentes dans
lequel les actionneurs sont commandés indépendamment pour faire varier la position
des basculeurs indépendamment, facultativement les actionneurs sont commandés par
des moyens informatiques programmables.
9. Générateur de mouvement selon l'une quelconque des revendications précédentes dans
lequel les éléments de connexion (46, 48, 50, 52, 54, 55) sont des organes résilients.
10. Générateur de mouvement selon l'une quelconque des revendications précédentes, qui
est inversable.
11. Système de mouvement comprenant un générateur de mouvement selon l'une quelconque
des revendications 1 à 10, et un système de commande associé.
12. Simulateur de véhicule (200) comprenant un générateur de mouvement selon l'une quelconque
des revendications 1 à 10 ou un système de mouvement selon la revendication 11, et
au moins un élément de simulateur de véhicule, de préférence l'élément de simulateur
de véhicule est choisi parmi un habitacle (206), une cabine de conduite, une commande
au pied, un volant (208), ou des moyens pour simuler un environnement (210).
13. Procédé de conception de véhicule ou de composant de véhicule, le procédé comprenant
les étapes consistant d'abord à fournir un générateur de mouvement selon l'une quelconque
des revendications 1 à 10, un système de mouvement selon la revendication 11, ou un
simulateur de véhicule (200) selon la revendication 12, puis à simuler une caractéristique
ou une modification de conception de véhicule ou de composant de véhicule et à tester
l'effet de cette caractéristique à l'aide du générateur de mouvement, du système de
mouvement ou du simulateur de véhicule.
14. Appareil de jeu à usage domestique ou commercial comportant un générateur de mouvement
selon l'une quelconque des revendications 1 à 10 ou un système de mouvement selon
la revendication 11, et facultativement comportant des moyens pour simuler un environnement
(210) tels qu'un appareil d'affichage, un appareil de réalité virtuelle, ou un appareil
de projection.